Chocolate is throughout the world regarded as being one of the finest types of confectionary and various types and shapes of chocolate confectionary have been developed over the years. The innovation within the field of chocolate has been much focused on sensory aspects, such as taste, and mouth feel. However, also the visual appearance is an important aspect in the consumer's overall perception of the quality of a chocolate confectionary. Accordingly, the visual appearance of a chocolate confectionary plays a key role for the chocolate manufacturer because a less attractive appearance of the confectionary will easily be judged by the consumer to relate to a confectionary of inferior quality.
An important problem relating to the visual appearance of a chocolate confectionary is the bloom effect which might take place in the coating of the chocolate confectionary. Such bloom effect is easily recognisable on the surface of that coating because in case a blooming has occurred, the coating of the confectionary will have a rather dull appearance having less gloss and often having clearly visible bloom crystals on the surface. The appearance of bloom, if any, typically takes place after weeks or months of storage.
Chocolate generally comprises cocoa butter, cocoa solids and sugar. Milk fat and/or milk proteins, emulsifies and other ingredients may be present in chocolate composition as well.
In the manufacturing process of chocolate, the ingredients are mixed refined and conched to a mixture. The mixture is subjected to a tempering process in a tempering apparatus in which the chocolate is subjected to a carefully pre-programmed temperature profile. Subsequently, the chocolate is used for making the chocolate confectionary (e.g. as a coating, a filling, a layer in a chocolate bar etc.) and the resulting confectionary is cooled following a predetermined cooling program.
The tempering process serves the purpose of making a sufficient amount of a desired type of seed crystals of the solid fats present in the chocolate, which in turns is responsible for obtaining a rather stable chocolate product which is less prone to changes in the crystal composition of the solid fats. The desired seed crystals are of the crystal form Form V. It is believed that the bloom effect occurring in chocolate confectionary is occasioned by polymorph transformation of fat crystals present in the chocolate.
Of the ingredients used for making chocolate, cocoa butter is by far the most expensive. For this reason, chocolate manufacturers have developed less expensive cocoa butter equivalents (CBE for short) which are compatible with cocoa butter in all ratios.
The general perception is that, mixing cocoa butter and/or cocoa butter equivalents with soft oils like soy oil, rapeseed oil, sunflower oil etc in a relative high content, may result in decrease in shelf life. It should be noted though, that bloom may also occur in a chocolate product in case the chocolate composition has been poorly tempered.
The bloom in chocolate coatings is a well studied phenomenon and among chocolate manufactures it is agreed that the bloom effect is inter alia occasioned by solid fat crystals transforming from the Form V to the Form VI crystal phase. Such recrystallisation into Form VI crystals may then accordingly result in bloom on the surface of the chocolate confectionary.
In the prior art various ways of avoiding the bloom effect in chocolates have been suggested. Such suggestions for avoiding bloom formation relate inter alia to optimising tempering conditions, adding high-melting milk fat fractions or sorbitan tristearate to the chocolate.
However, also specifically altering the TAG composition of a chocolate may lead to reduced bloom.
U.S. Pat. No. 5,524,090 accordingly discloses an anti-bloom agent comprising not less than 40% by weight of triglycerides of the form SatSatU, wherein Sat is a saturated fatty acid and wherein U is an unsaturated fatty acid, and wherein not less than 75% of all the Sat fatty acids are selected from the group comprising stearic acid and palmitic acid. In another embodiment, the content of the SatSatU triglycerides in the anti-bloom agent is not less than 20% by weight. The anti-bloom agent disclosed in U.S. Pat. No. 5,524,090 is intended for being added to a hard butter or a hard butter product, such as raw fats and oils, e.g. a cocoa butter product, such as chocolate in an amount that increases the content of SatSatU triglycerides in that product by 2-25%.
Addition of the anti-bloom agent according to U.S. Pat. No. 5,524,090 results in delayed formation of Form VI-crystals. A raise in the SatSatU content of cocoa butter by adding an anti-bloom agent according to U.S. Pat. No. 5,524,090 in an amount increasing the SatSatU content by 16% thus resulted in an decrease to 1.06 in the ratio of the x ray powder diffraction intensity of Form VI/Form V after 7 months storage, compared to cocoa butter having no such anti-bloom agent added, in respect of which the corresponding ratio was 1.63.
In an article of K. V. Smith et al. in Food Chemistry 102 (2007) 656-663 an investigation of the effect of formation of Form VI crystals by adding hazel nut oil to cocoa butter was published. The investigation reveals that adding hazel nut oil to cocoa butter significantly increases the rate of formation of Form VI crystals, even if the hazel nut oil was added in only minute amounts. Hazel nut oil in amounts of 0, 1, 2, 5, 10, 20% respectively were mixed with cocoa butter at 60° C. Thereafter, the mixtures were tempered and stores at 15, 20 and 25° C. X-ray diffraction was used to determine the progression of Form VI crystal formation. The results in the Smith article shows that after five weeks at 25° C., cocoa butter without hazel nut oil showed 28.3% Form VI, whereas cocoa butter comprising 20% hazel nut oil exhibited almost full transformation from Form V to Form VI. Even addition of 5% hazel nut oil in cocoa butter was able to lead to almost full transformation into form Form VI after ten weeks storage at 25° C.
Accordingly, the Smith article shows that even very small amounts of hazel nut oil in cocoa butter leads to considerable increased transformation from crystal Form V to Form VI.
Accordingly, in the art of chocolate manufacture there still exists a need for a fat composition which in a chocolate composition will act bloom retarding on the one hand, and which on the other hand will allow for cost savings in respect of the TAGs to be used in the chocolate composition.
It is the object of the present invention to provide such a bloom retarding fat composition.